Plaiting apparatus



Jufy 2, 1963 1.. J. PONSON ETAL 3,095,615

PLAITING APPARATUS Filed Aug. 22, 1961 3 Sheets-Sheet 1 INVENTORS 1 LLOYD J. PO/VSO/V ROBERT H. BECKER B WK.

ATTORNEY July 2, 1963 L. J. PONSON ETAL PLAITING APPARATUS Filed Aug. 22, 1961 3 Sheets-Sheet 2 July 2, 1963 L. J. PONSON ETAL 3,095,615

PLAITING APPARATUS Filed Aug. 22, 1961 3 Sheets-Sheet 3 INVENTORS LLOYDJ. PO/VSO/V ROBERT/1f BECKER 3,095,615 PLAITING APPARATUS Lloyd J. Ponson, Gulf Breeze, and Robert H. Becker, Pensacola, Fla, assignors to American Cyanamid Company, New York, N .Y., a corporation of Maine 7 Filed Aug. 22, 1961, Ser. No. 133,214 7 Claims. (Cl. 19-163) This invention relates broadly to plaiting apparatus and, more particularly, to apparatus for plaiting iiexible, elongated material. Still moreparticul arly it is concerned with apparatus whereby a fiat band of tow of synthetic filamentary material or its obvious equivalent can be deposited on an endless conveyor or other conveying mechanism without twisting or otherwise disarran-ging the band. The invention is applicable to any plaiting of filamentary or sheet material that must be transferred to a conveyor or the like for treatment of the material at speeds slower than the process speed. The present invention facilitates plaiting becauseit permits deposition of tow or the like on a conveyor without any twists, crossovers or disarrangement of the band of tow in any way.

No pertinent prior art is known. To the best of our knowledge and belief it was not known prior to the present invention \as to how a band of tow :or the like of filamentary or other material could be deposited on a moving conveyor without disarranging the tow. In certain processing operations it is imperative that the band of tow or the like should not be disarranged. The present invention is one solution to the problem and is, thus far, the best known solution.

It is a printary object of the present invention to provide a new and improved apparatus for plaiting a flexible, elongated material, e.g., a tow of filamentary material or the like.

It is another object of the present invention to provide United States Patent such apparatus whereby a tow of filamentary material or 1 the like can be plaited without twisting or otherwise disarranging the band of tow.

A further object of the invention is to provide a towplaiting technique whereby the frequency of the plait can be varied for any given product by controlling the height of the driven rolls above the conveyor.

Still another object of the invention is to provide means whereby, upon removal from the conveyor, all folds dis appear and the relative shape of the band of tow is unchanged.

Other objects of the invention will be apparent to those skilled in the art from the following more detailed description and from the accompanying drawing which is illustrative of a preferred embodiment of the invention.

The novel features of the invention are set forth in the appended claims. The invention itself, however, will be more readily understood from the following description taken in connection with the accompanying draw ing, which is illustrative of the invention, and wherein FIG. 1 is a plan view of one embodiment of the plaiting apparatus of the present invention and wherein two .toW-pla-iting units are shown depositing tow on a conveyor, the pattern formed by the tow being shown in somewhat exaggerated form;

FIG. 2 is an elewational view, partly in section, of one of the tow-plaiting units shown in FIG. 1, and illustrating somewhat schematically the deposition of tow on a conveyor;

FIG. 3 is a side elevational view, partly in section, of part of the tow-plaiting unit shown FIG. 2;

FIG. 4 is an elevational view of a portion of the right side of the tow-plaiting unit shown in FIG. 2;

FIG. 5 is an elevational view of a portion of the left side of the tow-plaiting unit shown in FIG. 2;

FIG. 6 is a front elevational view of a portion of the tow-plaitin g unit shown in FIG. 2; and

FIG. 7 is a plan view, taken along the lines 7-7 of FIG. 2, of the travel limit switches shown in said FIG. 2.

Referring now to the drawing and more particularly to FIG. 1 thereof, there is shown by way of illustration two bands of tow 10 and 12 of filamentary material, e.g., polyacrylonitrile filamentary material, being continuously laid down on the moving conveyor 14 by means of two tow-plaiting units 16 and 18, respectively. The arrows show the limit of movement of each unit.

Each band of tow is deposited on the conveyor in the approximate patterns designated as 20 and 22. It will be understood, of course, by those skilled in the art that the precise symmetry in the illustrated patterns of the deposited tow is seldom obtained in commercial practice due to variations in operating conditions that affect the symmetry of the pattern. The exact pattern will vary depending upon such influencing factors, as, for example, the production rate, and the vertical height of certain elements, specifically drawing means such as star nolls, above the conveyor. Also, when the tow being deposited i in wetted form, particularly wet gelled form, and the tow is being carried by the conveyor through a heated zone, the pattern of the deposited tow likewise may be infiu-enced by the residence time of the tow in such a heated zone.

' The invention obviously is not limited only to the use of a pair of plaiting units in depositing two bands of tow or the like on a moving conveyor as is shown in FIG. 1. Thus, a single plaiting unit or two, three, four, five or any higher number of such units can be employed as desired or as conditions may require.

Referring now to the other figures of the drawing and especially to FIGS. 2 and 3, the tow 10 is drawn by means of the driven star rolls 24 and 26 from a suitable supply source (not shown) but which commonly is a preceding step in the manufacturing operations.

The idler roll 28 (FIGS. 1 and 2) is supported by the idler shaft 30 (FIG. 1) and is provided with the idler roll cap 32. The bracket 33 holds the idler roll assembly in its desired position.

For optimum results the back edge of the idler roll shouldcoincide with the centerline of the shaft arm. When the idler roll is thusly positioned, lapping of the tow band or movement of the band from one side of the roll to the other is prevented.

The continuously moving tow passes under the idler roll 28, next under the guide bar 34 and then over the guide bar 36. The bar 34 is held in position by the slotted guide supports 38 (FIGS. 1 and 2), which are detachably attached to the plaiter arm 40 as shown in FIG. 2. The holes 42 in the side walls 44 of the plaiter arm 40 make it possible to change the position of the guide bar 34 at various points along the arm 44. The slots 46 in the guide supports 38 provide means for raising or lowering the guide bar 34 merely by attaching the supports 38 to the side walls 44 at a higher or lower point. I

The guide bar 36 is held in position by the supports 48, which are detachably attached to the top wall 50 of the plaiter arm 40. This may be done, for example, by

threading the ends of the supports 50 and screwing these ends into a threaded base adapted to receive said ends and which is fixedly or removably attached to the top wall 50. The height of the guide bar 36 above the wall 50 can be adjusted by using threaded rods of varying lengths as supports for guide bar 36. In this way there is provided one means for controlling the angle at which the tow 10 is passed between the star rolls 24 and 26.

The star rolls provide the pulling force to transport the tow 10 from a supply source to the moving conveyor 14. These rolls are positively driven by a motor and transmission system as shown in FIG. 3.

Referring particularly to FIG. 3 there is shown an electric motor 52 connected to a drive shaft 54 by means of a suitable coupling 56. This coupling can be, for example, a Lord coupling which is commercially available from the Lord Manufacturing Company, Erie, Pennsylvania. The motor is held in position by means of the motor brace 53. The cross brace 60 strengthens the rear end of the plaiter arm 40 as does also the stiffener plate 61. The motor 52 and drive shaft 54 are housed within the plaiter arm 40 having side walls 44 and 45, top wall 50 and bottom wall 66. The openings 68 in the side walls 44 and 45 of the plaiter arm permit inspection of the drive shaft 54 and, also, lighten the weight of the plaiter arm.

The forward end of the drive shaft 54 is connected to an angle gear unit 62 by means of a suitable coupling 64, such, for instance, as a Lord coupling of the kind mentioned above. The manner in which power is supplied to the star rolls is more clearly shown in FIGS. 4, and 6, especially when considered in connection with FIG. 3.

In FIGS. 4, 5 and 6 it is seen that right side plate 70 (FIGS. 4 and 6) and left side plate 72 (FIGS. 5 and 6) are held in position by the plaiter arm connection plate 74 and the tie rod '76.

Fiber gears '78 and 80 are shown in FIG. 3, while gear 80 only is seen in FIG. 6 and is there shown as being driven by the gear drive shaft 82 on which is positioned the shaft nut 84 adjacent the fiber gear 80.

Power for driving the shaft 86 of the star roll 26 is transmitted to said shaft by means of the gear-driven shaft 88, drive pulley 90, timing pulley 92 and timing belt 94. Housing for gear-driven shaft 88 is shown at 96. The right-hand side of FIG. 5 shows how power is transmitted from the gear-drive shaft 82 to the shaft 98 of the star roll 24 by means of drive pulley 100, timing pulley 162 and timing belt 104. Housing for shaft 82 is indicated at 106.

Suitable means are provided, e.g., as shown most clearly in FIGS. 4, 5 and 6, for protecting the deposition mechanism of the apparatus in case of a wrap up or other abnormal condition of or in the tow. For example, wrap-up protection can be provided with the aid of a micro switch that stops the driving mechanism of the star rolls when a wrap up causes the distance between between the star roll shafts to increase. Thus, in a pre ferred embodiment of the invention, the center distance of the star-roll shafts is fixed in one direction and is held there by a tension spring. When a wrap-up starts, the center distance increases and the micro switch stops the motor which drives the star rolls as previously has been described.

Referring now to the various figures of the drawing and especially to FIGS. 4, 5 and 6, it will be noted that right arm 108 is supported by the shaft 86 of star roll 26 and the short shaft 110. When a wrap-up or other abnormal condition arises the slot 112 in the right side plate 70 permits the shaft 86 bearing the star roll 26 to space itself from the shaft 98 bearing the star roll 24. Left arm 114 is supported by the shaft 86 of the star roll 26 and the housing 96 for gear-driven shaft 88. The slot 116 in the left side plate 72 serves the same function described above with reference to the right side plate 70.

Other elements of the star-roll control mechanism shown in FIGS. 4 and 6, and in part in other figures, are the arm tension spring 118, groove pin 120, and spring block 122, spring-tension screw 124, overload arm 126, overload shaft 128 and overload handle 130. In FIGS. 5 and 6, and in part in other figures, there are shown the arm tension spring 132, groove pin 134, spring block 136, spring tension screw 138, overload arm 140, overload shaft 142, and overload handle 144.

The micro switch carrier plate 146 is suitably attached to the front of the right side plate '70. To this plate is fastened the micro switch 148 which is connected by means of the electric cable 150 to the electric motor 52. The movable arm stops 152 and 153 are adjusted to maintain any desired center distance between the shafts of the star rolls. If and when a wrap-up starts, this center distance increases and the micro switch 148 is actuated, thereby stopping the motor 52 which drives the star rolls through the power-transmission means previously described.

The plaiting motion is provided by a Rotac torque actuator as shown in FIGS. 2 and 3, although any suitable means of providing such a motion may be used. The limits of the plaiting motion are controlled by the mechanism shown in FIG. 7. When the micro switches are actuated, they reverse the flow of fluid to the Rotac, thereby reversing the direction of the plaiting arm. The Rotac torque actuator is a commercial article which is available from Ex-Cell-O Corporation, Detroit 32, Michigan.

Referring particularly to FIGS. 2 and 3, it will be noted that the vertical column 154 is supported by the column support 156 having concrete base 158. To the column 154 are attached the Rotac supports 160 and 162, pillow block supports 164 and 166, and the micro switch support plate 168. The Rotac having inlet 172 for hydraulic fiuid from a supply source (not shown) is held in vertical position by the Rotac supports 160 and 162. The pillow block bearings 174 and 1'76 are supported by pillow block supports 164 and 166, respectively. The shaft ar-m 178 connects with the Rotac 170 through the Lovejoy coupling 186. The Lovejoy coupling is a commercial article which is available from Lovejoy Flexible Coupling (30., Birmingham, Alabama. The shaft arm 173 is provided at its upper end with the shaft arm plate 179.

To the spacer 182, which surrounds the shaft arm, is suitably fastened the knee brace support 184, and to the latter in turn is attached the knee brace 186 as shown in FIG. 2. This knee brace is angularly positioned (e.g., at an angle of 40 to 50) with respect to the spacer 182 and the plaiter arm 40, being fastened to said arm at 188.

The cam plate 190 is attached to the spacer 182 as shown in FIGS. 2 and 7. To this cam plate (see FIG. 7) are attached cams 192 and 194 by means of cap screws 196. Micro switches 198 and 200 (FIG. 7) are fastened to the micro switch support plate 168 which is fastened to column 154. The mechanism just described controls the limits of the motion of plaiting arm 40. When the micro switches are actuated by the movement of the cams 192 and 194, the flow of fluid to the Rotac is reversed and, consequently, the direction of movement of the plaiter arm 40 is reversed.

From the various figures of the drawing it will be seen the plaiter arm 40 is hollow, which is a preferred form, and that it is pivotally mounted at its rearward end to the upper end of a stationary support and at an angle of approximately 90 thereto. Such a stationary support is one which is comprised of the vertical column 154 suppggted by the column support 156 having a concrete base With further reference to FIG. 1, it will be noted that the tow-deposition mechanism also includes a roll end plate 202, a gear guard 204 and a pulley guard 206. A conveyor guard 208 is also provided.

In the operation of the tow-plaiting apparatus of this invention the tow is passed through the device in the manner which is clearly shown in FIGS. 1 and 2. As there shown, the tow passes under the idler roll 28, beneath the guide bar 34, over the guide bar 36 and to the nip between the star rolls 24 and 26. These star rolls pull the tow from a supply source to the moving conveyor 14 which carries the tow to the next operating step, for example, a drying step if the tow is in wetted or gelled form, in which case the tow may be conveyed to a drying and/or conditioning oven 210 or the like. In all cases the tow is moving at a much faster speed than the moving conveyor. For example, the tow speed may be from 75 to 150 meters/min. while the conveyor speed is only from 0.5 to 2 meters per minute. The oscillating speed of the plaiter arm 40 can be varied as desired or as conditions may require, e.g., from 3 to 20 strokes per minute, depending upon the tow and conveyor speeds.

Any suitable means can be employed for oscillating the plaiter arm 40, in addition to an air motor such as the Rotac torque actuator mentioned hereinbefore and shown in various figures of the accompanying drawing. Another means is a mechanical linkage whereby the angular speed of the plaiter arm can be varied.

The frequency of the plait can be varied by changing the distance between the star rolls and the surface of the moving conveyor. For example, in laying down a tow of a gelled polyacrylonitrile filamentary material on a conveyor, the height of the star rolls above the conveyor surface may range from to 20 inches.

The speed at which the tow passes between the star rolls and its weight pushes the tow forward and backward. The length of the plait depends, for example, upon the speed of the tow and its weight, the latter being especially true in the case of a tow in aquagel form and which in such form may contain, for example, from 60% to 70% by weight of water.

The plaiting action produced by the apparatus of this invention produces no full twists at any time. However, it does produce a series of false twists with a frequency of twice the length of the piddle. The piddle length is shown at 212 in FIG. 2. The false twist is automatically removed when the tow is lifted from the conveyor. Hence, the tow band is always under control, and its shape is never deformed.

The plaiting apparatus of this invention is suitable for use whenever it is necessary to treat a flexible, elongated article (e.g., a flexible article of continuous or indefinite length) at a speed slower than the process speed. The apparatus is especially useful when the residence time during a drying or other treatment to be effected is so long that the cost would be prohibitive or excessive if a straight-through unit were employed. The apparatus of this invention permits a tow of filamentary material or its obvious equivalent to be deposited on a slowly moving conveyor in such a manner that the required residence time in the process step that follows can be achieved without twisting, disarranging or otherwise disturbing the band.

We claim:

1. Plaiting apparatus comprising a stationary support; a plaiter arm pivotally mounted at its rearward end to the upper part of said support and at an angle of approximately 90 thereto; a housing attached to the forward end of said arm, said housing being adapted to permit the direct passage therethrough of a tow of filamentary material; means for oscillating, for a controlled distance, said arm and the housing attached to its forward end; drawing means including cooperating star rolls for drawing the said tow to the said housing; means for driving said star rolls; and a plurality of guide means positioned above and along the said arm for guiding the said tow to the said drawing means.

2. Plaiting apparatus comprising a stationary support; a hollow plaiter arm pivotally mounted at its rearward end to the upper end of said support and at an angle of approximately 90 thereto; a housing having side walls, said housing being attached to the forward end of said arm and being adapted to permit the direct passage therethrough of a tow of filamentary material; means including an air motor for oscillating, for a controlled distance, said arm and the housing attached to its forward end; a pair of cooperating star rolls within the said housing and the ends of which are adjacent to the said side walls, said star rolls being adapted to draw the said tow to the nip of the said rolls; means including an electric motor for driving said star rolls, said motor being positioned within the said hollow plaiter arm near its rearward end; and a plurality of guide means positioned above and along the said arm for guiding the said tow to the said star rolls.

3. Plaiting apparatus as in claim 2 which additionally includes means for causing the distance between the shafts supporting the star rolls to increase when an abnormal condition develops in the tow at the nip between the said star rolls.

4. Plaiting apparatus as in claim 3 which additionally includes adjustable means for maintaining any desired center distance between the shafts supporting the star rolls; and a micro switch connected to the said electric motor, said micro switch being in operative relationship with the said adjustable means and being actuated when the center distance between the shafts supporting the star rolls is increased during operation of the apparatus above the normal center distance, thereby stopping the said motor and, consequently, the said star rolls when the said micro switch is actuated.

5. Plaiting apparatus comprising a stationary support; a plaiter arm pivotably mounted at one end thereof to said support; a pair of driven cooperating star rolls mounted near a second end of said plaiter arm with the axes of said star rolls substantially perpendicular to the length of said plaiter arm; means for oscillating said plaiter arm; and means for guiding a tow along said plaiter arm from said one end to said star rolls.

6. Plaiting apparatus comprising a conveyor belt; means for moving said conveyor belt at a relatively low speed; a stationary support; a plaiter arm pivotably mounted at one end thereof to said support; a pair of cooperating star rolls mounted near a second end of said plaiter arm above said conveyor belt; means for oscillating said plaiter arm whereby said star rolls reciprocate axially across said conveyor belt; means for rotating said star rolls at a relatively high peripheral speed; and means for guiding a tow to be plainted along said plaiter arm from said one end to said star rolls.

7. Plaiting apparatus comprising a stationary support; a plaiter arm; pivot means for securing one end of said plaiter arm to said support; a pair of driven cooperating star rolls mounted near a second end of said plaiter arm; means for oscillating said plaiter arm about the axis of said pivot means; and means for guiding a tow along said plaiter arm from said one end to said star rolls, said last mentioned means including deflection means positioned to deflect moving tow from a direction along the axis of said pivot means to a direction along said plaiter arm.

References Cited in the file of this patent UNITED STATES PATENTS 267,513 Gessner Nov. 14, 1882 1,610,209 Schimek Dec. 7, 1926 2,308,849 Young Jan. 19, 1943 2,710,992 Goldman June 21, 1955 2,986,781 Jackson et a1. June 6, 196 1 FOREIGN PATENTS 1,143,606 France Apr. 15, 1957 

1. PLAITING APPARATUS COMPRISING A STATIONARY SUPPORT A PLAITER ARM PIVOTALLY MOUNTED AT ITS REARWARD END TO THE UPPER PART OF SAID SUPPORT AND AT AN ANGLE OF APPROXIMATELY 90* THERETO; A HOUSING ATTACHED TO THE FORWARD END OF SAID ARM, SAID HOUSING BEING ADAPTED TO PERMIT THE DIRECT PASSAGE THERETHROUGH OF A TOW OF FILAMENTARY MATERIAL; MEANS FOR OSCILLATING, FOR A CONTROLLED DISTANCE, SAID ARM AND THE HOUSING ATTACHED TO ITS FORWARD END; DRAWING MEANS INCLUDING COOPERATING STAR ROLLS FOR DRAWING THE SAID TOWS TO THE SAID HOUSING; MEANS FOR DRIVING SAID STAR ROLLS; AND A PLURALITY OF GUIDE MEANS POSITIONED ABOVE AND ALONG THE SAID ARM FOR GUIDING THE SAID TOW TO THE SAID DRAWING MEANS. 